Draft-tube for hydraulic turbines.



F. B. RYONS QM. A. REPLOGLE. DRAFT TUBE FOR HYDRAULIC unmfs.

APPLICATION FILED SEPT. 1| |914.

Patentedsept. 26,1916.

Wl TNESSES BY .am@14/ A TTORNEY m r .wwms Perses co., naam-uma., wAsnmc ruw, n. c.

funrrnn sfrarns PATENT @mime FRED B. RYONS, OF LINCOLN, NEBRASKA, AND MARK A. REPLGGLE, OF AKRON, OHIO.

DRAFT-TUBE FOR HYDRAULIC TURBINES.

To all 'whom t may concern Y Be it known that we, FRED B. RYONS and MARK A. RnrLoeLE, citizens of the United States, and residing, respectively, at Lincoln, Nebraska, and Akron, Ohio, have jointly invented the improvements in Draft- Tubes for Hydraulic Turbines as herein described.

This invention relates to the construction, equipment and operation of draft tubes for hydraulic turbines.

The objects of the invention are to provide for increasing the speed and power of water turbines operating under a given head, to reduce the size of turbine needed to deliver a given amount of power under a given head, to furnish means for varying the speed and power of the turbine, to prevent diminution of speed or power due to fall or loss of head during high water or flood times, and to provide for utilizing surplus water at any time to increase the speed and power of such turbines.

The accompanying drawing shows a construction sufficiently clear to enable others to make and use our device.

Before referring in detail to the drawing, it may be noted it is known in the present state of the art that to economically get energy by turbine from a descending column of water, the water should descend through a closed conduit or pipe whose function is to produce a very rapid motion `at some narrowed portion or throat thereof; and that the turbine should be located so that its ports are in eect above the throat, but its passage vents in the aggregate actually constitute said throat or an integral portion of it. Designating the water actually passed through the turbine as the primal column, we accelerate this primal column bya draft tube which is arranged as an extension of the turbine discharge pipe; and further accelerate it, when desired, by an auxiliary column which also accelerates itself by utilizing part of the identical throat which is designed to accelerate the primal column when the auxiliary column is'exeluded. We lhave discovered that in order to get Vthe best effect of the auxiliary column, the throat of the primal column should be extended to a point where the auxiliary column may be united with it Vat the maximum accelerated speed of the combined columns,l and that the auxiliary column should be moving in the :same direction as wellvas at the same speed.,

Specification of Letters Patent.

Patented Sept. 28, 1916.

Application led September 1, 1914. Serial 1\T o. 859,658.

at the time of merging with, and at point of Junction with said primal column.

llhe function of our device now having been set forth, it may be more fully explained by reference te the drawing in which- Figure 1 is a view mostly in vertical section, ofa forebay with turbine installation embodying our accelerator. Fig. 2 is an under side view of the main features of such installation. Fig. 3 is a view at right angles of part of control mechanism shown in Fig. 1.

Referring to the views, 1 denotes a vertical turbine within a penstock 18 having ports 1 controlled by a pinion 17 carried by a shaft 16 and hand wheel 6. The turbine is supported by beams 15, 15, and has a curved discharge pipe 2 over the lower end of which lits the sliding gate 3. rlhis gate is a cylindrical ring having toothed rack arms, l secured to it at 4', i, pinions 5, 5 engaging with said arms and said pinions being arranged to be driven vby the shaft 7 carrying the chain sprocket 8 connecting with sprocket 8 on shaft 7 carrying the hand wheel G, all supported by hangers bolted to the floor 14 as shown in Fig. 3. f

An infuser 9 which may be constructed as a single casting is set solidly in the wall 1:2 of the penstock 18, its flaring' mouth 9 concentric-ally encircling the sliding ring gate 3. The infuser and ring gate must be kept in axial alinement and a pier 13 to which the discharge pipe 2 is anchored serves this purpose. To the flange 1() of .the infuser a flaring draft tube 11 connects making continuous inner walls. rlhe diameter of the draft tube at the flange 10 corresponds closely with the throat diameter 9 of the infuser, and also with the diameter of the discharge pipe 2; but it should increase in diameter outward at a rate equal to about one sixteenth part of the throat diameter to each foot of length, the length being indefinite or limited to conditions at point of installation. ln the larger installations the draft tube 11 will for the most part be constructed of concrete or masonry, but is here shown as of metal. lt is intended to represent the infuser as leading through the wall ofthe penstock 18 which supplies water to the turbinev and infuser from a common head or upper level as 19 at low wate'r and 2O at high weten and itis to be understood Veo lov-.fY tail water indicated by the level 19.

in Vthe operation of the device at low water, the rin'" gate S is to be setin the closed positie rim 3 iinpinging on the race of the infuser throat 9 in J of the dotted line. ln this position n draft tube performs the usual function on f. ln cese of excess of water such as would tend to raise the level of the water in the penstcck, say from level 19 to level and the level below spillway from 19 o 29, the apparent head or difference be- `Ween levels of head water and tail water, .rould be materially decreased. Under the Vattei conditie-ns the ring gate 3 is to be slid back, by means of the'hand wheel, allowing an annular opening between ,its rim'B and the concave surface of the infuser throat 9 through which opening an annular auxiliary stream is inducted to give greater velocity .to the outgoing water inthe draft tube 11.`

The result of this is to remove'part lof the atmospheric pressure frein-the lower end of the discharge pipe 2, and therefore to accelerate the discharge and flow through the turbine and ,increase its power. While of course not all of the energy 0f the inducted stream is effective in the turbine, yet so great a volume may be thusinducted, if need be, that the power of the turbine may be brought to double or treble what itwould be without this auxiliary.

lille are aware that auxiliary streams have been inducted into turbine draft tubes heretofore, for this purpose, but the induction has been effected at points beyond, and in effect below the throat, instead of in, andl in effect above the throat `of the main conduit as we do it. Y auxiliary conduit having a throat formed by its inner surface and the rim of the ring gate, within the throat of the main conduit,

in effect, so that the primal column of water and the auxiliary column of water meet at the place of greatest velocity ofthe coinbined columns; it being understood that the dischargepipe 2 is essentially a prolonged throat, and may be in straight axial alinement with. the turbine or curved as Vshown provision always being made for room and connections to operate the ring gate 3.

Having thus described the inventionand operation thereof, what we claim and desire to secure by Letters Patent is:

.1. The l combination with a hydraulic turbine, of'a discharge pipe of substantially uniform diameter reaching below the low level of tail water, an extension sleeve slid-Y ably connected to the outer end of said discharge pipe, means for sliding said sleeve longitudinally of the pipe, an .expanding draft tube havingrits smaller end of a diameter substantially equal to that of the Qur infuser constitutes an discharge pipe aforesaid,'arranged in axial alinement of said discharge pipe, andl having a funnel shaped infuser extending from its smaller end which surrounds Ysaid sliding sleeve, and said sleeve beine,` adapted:V to

close the gap between the discharge pipey andthe draft tube aforesaid, by impinge.

ment on the inner surface of the narrowest diameter of the infuser aforesaid.

2. A hydraulic accelerator for turbines comprising a penstock containing the turbine, a discharge pipe of uniform diameter attached to the turbine and reaching belowY the low level of tail water, a slidable gateor sleeve on the end of said pipe, means for moving said sleeve longitudinally of the i e an ex andino draft tube leading fromthe penstock and having a neck of a diiameter substantially equal to that of the pipe, a funnel-shaped infuser in the penstock wall, secured -to said neck and arranged in axial alinement with andconcentrically surrounding the/outer end of said sleeve, and said sleeve adapted to im.-

pinge on the inner surface of the infuser at its narrowest part for the purpose set forth. f

3. In combination with a penstock of` l turbine draft tube leading therefrom-and having a narrowed Vneck or throat located below the level of tail water, of an infusei'` in the penstock wall constituting lpart of said throat, a flaring `rim of the infuser within the penstoek. adapted to induct water `from theV penstockf into the drafttube, a discharge pipe leading from the* turbine `and f having a diameter substantially equal to that ofsaid throat, and ar- Y rangedto diseharge'water into said Iinfuser` coincidentally with that inducted from. the penstock for the purpose' set forth. s

4L. The herein described accelerator ,for

water turbines, comprising a penstock, a

discharge pipe of theturbine leadingoutward of the penstock, an expanding drafttube having a throat of equal diameter to that of the discharge pipe located'in the wall of the penstock and below the level of tail water but; arranged in axial alineinent iio tube adapted to carry discharge water and auxiliary water and having a throat VorA narrow neck therein, of a discharge pipe,"

inductzauxilary water into said draft tube. Y

at said throat and below the level of tail Water, the Walls of said draft-tube expanding outward down stream from the throat at a gradual increase in diameter.

6. The combination With a hydraulic turbine, of a discharge pipe extending below the level of tail Water, an expanding drafttube having a neck of a diameter substantially equal to that of the discharge pipe, and a funnel-shaped infuser extending from said neck, in axial alinernent with the end of said discharge pipe, and surrounding the end thereof for the purpose set forth.

7. rThe combination with a hydraulic tur- 15 bine of a discharge pipe of uniform diarneter, an expanding draft tube having a neck, and a funnel-shaped infuser extending from said neck substantially in axial alineinent with the end of the discharge pipe and surrounding said end, for the pur- 20 pose set forth.

FRED B. RYONS. MARK A. REPLOGLE.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of .'Patentl, Washington, D. C. 

